The long-term goal of this proposal (Phase I and II) is to develop a human monoclonal antibody-based preparation for use in treating CMV infections or transmission. Commercial applications for human monoclonal antibodies are extensive. Phase I specific aims are: 1) Screen matching plasma of random buffy coats to identify CMV immune donors, and engraft selected donor cells in SCID mice (hu-PBL-SCID system). 2) Immunize with recombinant gB or gH proteins (neutralizing targets for CMV), and detect specific serum antibodies by ELISA. Optional EBV super-infection may be used. 3) Harvest cells from selected mice, and isolate antigen specific human B/plasma cells by a novel method (antibody rescue technology). Clone heavy and light chain V regions from cells by RT-PCR. 4) Isolate transiently transfected cells producing antigen-specific human monoclonal antibodies. Characterize these for epitope group, affinity, neutralizing capacity, and strain specificity. The main goal of the phase II proposal will be the configuration of at least one combination of human monoclonals for treatment of CMV infection. The phase II SBIR proposal may initially require the leneration of a larger panel of antibodies, based on the success of phase I.